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1.
PLoS One ; 19(4): e0297903, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38626021

RESUMO

Social networks often involve the users rating each other based on their beliefs, abilities, and other characteristics. This is particularly common in e-commerce platforms where buyers rate sellers based on their trustworthiness. However, the rating tends to vary between users due to differences in their individual scoring criteria. For example, in a transaction network, a positive user may give a high rating unless the transaction was unsatisfactory while a neutral user may give a mid-rating, consequently giving the same numeric score to different levels of satisfaction. In this paper, we propose a novel method called user tendency-based rating scaling, which adjusts the current rating (its score) based on the pattern of past ratings. We investigate whether this rating scaling method can classify between "good users" and "bad users" in online trade social networks better when compared with using the original rating scores without scaling. Classifying between good users and bad users is especially important for anonymous rating networks like Bitcoin transaction networks, where users' reputations must be recorded to preclude fraudulent and risky users. We evaluate the proposed rating scaling method by performing user classification, link prediction, and clustering tasks, using three real-world online rating network datasets. We use both the original ratings and the scaled ratings as weights of graphs and use a weighted graph embedding method to find node representations that reflect users' positive and negative information. The experimental results showed that using the proposed rating scaling method outperformed using the original (i.e., unscaled) ratings by up to 17% in classification accuracy, and by up to 2.5% in link prediction based on the AUC ROC measure, and by up to 21% in the clustering tasks based on the Dunn-index.


Assuntos
Comércio , Rede Social
2.
Front Chem ; 11: 1090648, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37035119

RESUMO

The corrosion mechanism and kinetics of the silver-coated conductive yarn (SCCY) used for wearable electronics were investigated under a NaCl solution, a main component of sweat. The corrosion occurs according to the mechanism in which silver reacts with chlorine ions to partly form sliver chloride on the surface of the SCCY and then the local silver chloride is detached into the electrolyte, leading to the electrical disconnect of the silver coating. Thus, the electrical conductance of the SCCY goes to zero after 2.7 h. The radial part-coating of gold, which is continuously electrodeposited in the longitudinal direction on the SCCY but is partly electrodeposited in the radial direction, extends the electrical conducting lifetime up to 192 h, despite the corrosion rate increasing from 129 to 196 mpy (mils per year). Results show that the gold partly-coating on the SCCY provides a current path for electrical conduction along the longitudinal direction until all the silver underneath the gold coating is detached from the SCCY strands, which creates the electrical disconnect. Based on the corrosion behavior, i.e., local oxidation and detachment of silver from the SCCY, the gold part-coating is more cost effective than the gold full-coating electrodeposited on the entire surface for electrically conducting SCCY.

3.
Comput Biol Med ; 149: 106041, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36049411

RESUMO

BACKGROUND: Saeng-Ji-Hwang-Ko (SJHK) is a traditional Korean medicine formula derived from Donguibogam, a classic medical textbook, published in 1613. It is described as a general treatment for So-gal (wasting-thirst, ) known as type 2 diabetes mellitus (T2DM) in a modern clinical term. It is necessary to elucidate the potential compounds and targets of SJHK for T2DM treatment by conducting network pharmacology and molecular docking analyses. METHODS: Information about the chemical constituents of SJHK were collected, and druggable compounds were screened based on oral bioavailability and drug-likeness. Putative target genes of druggable compounds and T2DM-related genes were retrieved from public databases. A compound-target network was constructed to visualize the relationship between the druggable compounds in SJHK and common targets related to T2DM. The constructed network was further investigated through Protein-Protein Interaction, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway analyses, and molecular docking. RESULTS: Compound-target network analysis demonstrated that kaempferol, salicylic acid, estrone, and ß-sitosterol were key compounds of SJHK with PTGS2, ESR1, PRKAA2, PRKAB1, and CYP19A1 being its key targets. Estrogen signaling, AGE-RAGE signaling, insulin resistance, non-alcoholic fatty liver disease, and TNF signaling pathway were potential pathways involved in the effect of SJHK on T2DM. Molecular docking simulations revealed that estrone and ß-sitosterol had the strong binding energies for all the key target proteins. CONCLUSIONS: This study demonstrates that network pharmacology and molecular docking analyses help to better understand the potential key compounds and targets of SJHK for treating T2DM as a complementary medicine. SUMMARY: Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder caused by genetic and/or environmental factors. There has been a growing attention to new therapeutic approaches to treat T2DM using traditional medicine as a complementary treatment which is expected to have synergistic effects with few side effects. Saeng-Ji-Hwang-Ko (SJHK) is a traditional Korean medicine (TKM) formula derived from Donguibogam, a classic medical textbook, published in 1613. It is described as a general treatment for So-gal (wasting-thirst, ) known as type 2 diabetes mellitus (T2DM) in a modern clinical term. It is necessary to elucidate the potential compounds and targets of SJHK for T2DM treatment by conducting network pharmacology and molecular docking analyses. Compound-target network analysis demonstrated that kaempferol, salicylic acid, estrone, and ß-sitosterol were key compounds of SJHK with PTGS2, ESR1, PRKAA2, PRKAB1, and CYP19A1 being its key targets. Estrogen signaling, AGE-RAGE signaling, insulin resistance, non-alcoholic fatty liver disease, and TNF signaling pathway were potential pathways involved in the effect of SJHK on T2DM. Molecular docking evaluation revealed that estrone and ß-sitosterol had the highest binding energies for all key target proteins, suggesting potential key compounds of SJHK. Although additional future studies including further experimental and clinical validation are needed, this study demonstrates that SJHK has a great potential for treating T2DM as a complementary medicine.


Assuntos
Diabetes Mellitus Tipo 2 , Medicamentos de Ervas Chinesas , Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Ciclo-Oxigenase 2/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Estrogênios/uso terapêutico , Estrona/uso terapêutico , Humanos , Quempferóis/uso terapêutico , Simulação de Acoplamento Molecular , Farmacologia em Rede , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ácido Salicílico/uso terapêutico
4.
Artigo em Inglês | MEDLINE | ID: mdl-35969550

RESUMO

Proactively detecting falls and preventing injuries are among the primary keys to a healthy life for the elderly. Near-fall remote monitoring in daily life could provide key information to prevent future falls and obtain quantitative rehabilitation status for patients with weak balance ability. In this study, we developed a deep learning-based novel classification algorithm to precisely categorize three classes (falls, near-falls, and activities of daily living (ADLs)) using a single inertial measurement unit (IMU) device attached to the waist. A total of 34 young participants were included in this study. An IMU containing accelerometer and gyroscope sensors was fabricated to acquire acceleration and angular velocity signals. A comprehensive experiment including thirty-six types of activities (10 types of falls, 10 types of near-falls, and 16 types of ADLs) was designed based on previous studies. A modified directed acyclic graph-convolution neural network (DAG-CNN) architecture with hyperparameter optimization was proposed to predict fall, near-fall, and ADLs. Prediction results of the modified DAG-CNN structure were found to be approximately 7% more accurate than the traditional CNN structure. For the case of near-falls, the modified DAG-CNN demonstrated excellent prediction performance with accuracy of over 98% by combining gyroscope and accelerometer features. Additionally, by combining acceleration and angular velocity the trained model showed better performance than each model of acceleration and angular velocity. It is believed that information to preemptively handle the risk of falls and quantitatively evaluate the rehabilitation status of the elderly with weak balance will be provided by monitoring near-falls.


Assuntos
Acidentes por Quedas , Aprendizado Profundo , Acidentes por Quedas/prevenção & controle , Atividades Cotidianas , Idoso , Algoritmos , Humanos , Monitorização Ambulatorial
5.
Pharmaceutics ; 13(7)2021 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-34371784

RESUMO

Prostate and breast cancer are the current leading causes of new cancer cases in males and females, respectively. Phosphatidylserine (PS) is an essential lipid that mediates macrophage efferocytosis and is dysregulated in tumors. Therefore, developing therapies that selectively restore PS may be a potential therapeutic approach for carcinogenesis. Among the nanomedicine strategies for delivering PS, biocompatible gold nanoparticles (AuNPs) have an extensive track record in biomedical applications. In this study, we synthesized biomimetic phosphatidylserine-caped gold nanoparticles (PS-AuNPs) and tested their anticancer potential in breast and prostate cancer cells in vitro. We found that both cell lines exhibited changes in cell morphology indicative of apoptosis. After evaluating for histone-associated DNA fragments, a hallmark of apoptosis, we found significant increases in DNA fragmentation upon PS-AuNP treatment compared to the control treatment. These findings demonstrate the use of phosphatidylserine coupled with gold nanoparticles as a potential treatment for prostate and breast cancer. To the best of our knowledge, this is the first time that a phosphatidylserine-capped AuNP has been examined for its therapeutic potential in cancer therapy.

6.
Front Chem ; 7: 415, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31245354

RESUMO

ZnO nanorods (NRs) decorated with Ni nanoparticles were synthesized using a template-free electrochemical deposition in an ultra-dilute aqueous electrolyte and a subsequent galvanic reaction. The electrochemical properties of the ZnO NRs as an anode material for rechargeable Li-ion batteries were evaluated for different binder morphologies (film and close-packed spherical particles) of polyvinylidene fluoride (PVDF). Results showed that the close-packed spherical PVDF simultaneously improved electrochemical capacity and cyclability because the free-volume between the spherical PVDF helped to accommodate the volume change in the anode caused by the Li ions discharge and charge processes. Furthermore, the Ni nanoparticles decorated on the surface of ZnO NRs enhanced the electrical conductivity of the ZnO NR anode, which enabled faster electronic and ionic transport at the interface between the electrolyte and the electrode, resulting in improved electrochemical capacity. The free-volume formed by the close-packed spherical PVDF, and the decoration of metal nanoparticles are expected to provide insight on the simultaneous improvement of electrochemical capacity and cyclability in other metal oxide anode nanostructures.

7.
Nanotechnology ; 28(18): 18LT01, 2017 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-28346218

RESUMO

Semiconducting two-dimensional (2D) materials, particularly extremely thin molybdenum disulfide (MoS2) films, are attracting considerable attention from academia and industry owing to their distinctive optical and electrical properties. Here, we present the direct growth of a MoS2 monolayer with unprecedented spatial and structural uniformity across an entire 8 inch SiO2/Si wafer. The influences of growth pressure, ambient gases (Ar, H2), and S/Mo molar flow ratio on the MoS2 layered growth were explored by considering the domain size, nucleation sites, morphology, and impurity incorporation. Monolayer MoS2-based field effect transistors achieve an electron mobility of 0.47 cm2 V-1 s-1 and on/off current ratio of 5.4 × 104. This work demonstrates the potential for reliable wafer-scale production of 2D MoS2 for practical applications in next-generation electronic and optical devices.

9.
J Nanosci Nanotechnol ; 10(11): 7060-4, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21137865

RESUMO

High-resolution studies of self-assemblies of semifluorinated alkanes molecules F12H8 and F14H20 [FnHm = CF3(CF2)n(CH2)mCH3], and CdTe particles were performed with single-pass Kelvin force microscopy. Surface potential contrast, which is related to the strength and orientation of molecular dipoles, empowers the characterization of self-organized structures. Lamellar structures, ribbons and toroids of F14H20 and F12H8 were observed on graphite and the differences of surface potential were interpreted in terms orientation of -CH2-CF2- dipoles. A gradual sublimation of F12H8 molecules allowed a visualization of top and bottom molecular layers on the substrate. Prior to the sublimation a part of lamellae of the bottom layers was transformed into the ribbons. The surface potential data suggest that this transition proceeds with the reorientation of the molecular chains from the horizontal to vertical direction. Self-assembly of CdTe nanoparticles into nanowires was monitored upon drying on mica. The process is accompanied by drastic changes of surface potential. The formed nanowires exhibit strong positive surface potential that assumes a structural transition with a formation of strong dipole moment in these self-assemblies.

10.
Chem Commun (Camb) ; (9): 1052-4, 2009 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-19225633

RESUMO

Without any catalysts or feeding source gases, highly crystalline Cr nanowires were directly synthesized on a flexible polymeric substrate using microwaves and the surface of the as-grown Cr nanowires showed superhydrophobicity.

11.
Small ; 1(5): 553-9, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-17193485

RESUMO

Vertically aligned carbon-nanotube (CNT) arrays were fabricated in the thin-film anodic aluminum oxide (AAO) templates on silicon wafers utilizing a niobium (Nb) thin film as the source electrode. The average diameter of the CNTs was 25 nm, and the number density was 3 x 10(10) cm(-2). The CNT arrays synthesized at 700 degrees C and above exhibited Schottky behavior even at 300 K, with energy gaps between 0.2 eV and 0.3 eV. However, individual CNTs obtained by removal of the template behaved as resistors at 300 K. The CNT/Nb oxide/Nb junction is thought to be responsible for the Schottky behavior. This structure can be a useful cornerstone in the fabrication of nanotransistors operating at room temperature.


Assuntos
Nanotecnologia/métodos , Nanotubos de Carbono/química , Nióbio/química , Alumínio/química , Carbono , Eletroquímica , Eletrodos , Eletrônica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanopartículas , Nanotecnologia/instrumentação , Óxidos/química , Silício/química , Temperatura , Transistores Eletrônicos
12.
J Am Chem Soc ; 126(49): 15982-3, 2004 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-15584730

RESUMO

A chemical route to single-walled carbon nanotubes (SWCNTs) under ambient conditions has been developed. Silica powder was immersed in a mixture solution of ferrocene and p-xylene. After sonication at atmospheric pressure and room temperature, we obtained high-purity SWCNTs. Sonochemical effects may lead to producing high-purity SWCNTs. The process could be readily generalized to synthesize other forms of carbon-based materials, such as fullerenes, multiwalled nanotubes, carbon onions, and diamond, in liquid solution under ambient conditions.


Assuntos
Compostos Ferrosos/química , Nanotubos de Carbono/química , Dióxido de Silício/química , Xilenos/química , Pressão Atmosférica , Metalocenos , Soluções , Sonicação , Análise Espectral Raman
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